Lens reviews update: test data for the Nikon 58mm f/1.4G

DxOMark has recently reviewed Nikon's AF-S Nikkor 58mm f/1.4G, a high-end (and very expensive) standard prime for full frame SLRs. As a taster for our upcoming review we've added the test data to our lens widget; as usual you can compare it to similar lenses, including the Nikon and Sigma 50mm F1.4s. Click through for more details and analysis, and a link to DxOMark's own review of the Nikon 58mm F1.4.

Nikon AF-S Nikkor 58mm f/1.4G lens test data

Here we're showing DxOmark's lens test data for the 58mm f/1.4 on both the full frame D800 and the DX format D7100, along with a quick summary of the main findings. We're also showing a quick comparison to the existing AF-S Nikkor 50mm f/1.4G. After some real-world shooting with the 58mm, though, it's become pretty clear to us that this doesn't quite tell the full story. We'll look at this in more depth in our upcoming full review.

Click on any of the images or links below to open our interactive lens widget, and explore the data further

1) Tested on Nikon D800

On the D800, sharpness isn't especially high wide open, but this is entirely to be expected from a fast prime. Central sharpness increases rapidly on stopping down, but the edges lag behind significantly. This likely reflects curvature of field as much as anything else (these tests use a flat chart focused for the highest central sharpness). The edges continue to sharpen up at smaller apertures, and by F11 come close to matching the centre.

In all other respects the 58m performs extremely well. Lateral chromatic aberration is very low, and unlikely to be problematic in normal use, even without correction. Vignetting is unusually low for a fast prime: just 1.3 stops wide open, dropping to 0.7 stops at F2, and with a relatively gentle falloff in illumination into the corners (which should make it visually unobtrusive). There's a little barrel distortion, but its simple profile means it should be easy to correct in software when necessary.

2) Tested on Nikon D7000

It's very much the same story on the DX format D7000 as on full frame. Sharpness isn't great wide open, but it improves dramatically on stopping down - by F4 the centre of the frame is as sharp as it's going to get. The corners again lag behind, but sharpen up very well by F8. Chromatic aberration is pretty low, and unlikely to be anything to worry about in normal shooting. As usual for a full frame lens on DX, vignetting and distortion are very low indeed.

3) Compared to the AF-S Nikkor 50mm f/1.4G

The studio tests don't give a clear edge to the 58mm f/1.4 over its much-less-expensive 50mm f/1.4 stablemate. Central sharpness is higher, but on the other hand the edges are softer. Chromatic aberration and vignetting are both lower on the 58mm, while distortion is about the same.

Overall, from these test results alone it's not totally straightforward to see why the 58mm f/1.4 costs so much compared to the 50mm. But after shooting a little with the 58mm, it's clear that they don't tell the entire story about the lens. Stay tuned for our upcoming review to get a fuller picture into what it offers.

Full test results on DxOMark (and other recent reviews)

Our lens test data is produced in collaboration with DxOMark. Click the links below to read DxOMark's own review of the Sigma 120-300mm F2.8 DG OS HSM, or see other recent reviews on the DxOMark website.

Our expectation was high for this lens based on the price that now clearly does not reflect the performance. When the standard 50mm out performs at a quarter of the price why would anyone purchase it? The little benefit it gains in night work does not justify the high price when standard lenses are comparable. This is one for the birds!

personally, I consider this type of lens absolutely useless without af. take a portrait session, glamor sitting, model shoot, wedding, it boils down to being able to capture a moment or an expression of something deeper, something symbolic about the event or something revealing about a character, a tear rolling down the groom's cheek before he quickly wipes it off, a heartfelt laugh of a CEO, etc, now try to manual focus that with your incredible Otus, not totally impossible if luck is on your side but almost for most mortals :)

Detail as in the ability to produce a sparkling clean image so that a viewer can get lost in the beauty and infinite detail of a landscape or the joy in a portrait of a child, or so a client will see with new eyes the handsomeness of his product. I want a lens that allows viewers to look and not be distracted by weird color aberrations or perspective distortions or awkward transitions between in focus and out of focus.

Well - don't shot me - but I thought the WHOLE idea of this lens was that it WOULD be SUPER SHARP wide open ...? If not then frankly was is the point? The 50 1.8 bog basic lens is pretty good and a TON of money less. Seems that Nikon have failed to do a ZEISS !

Next up - bring on the Canon 50 1.2 L MK2 (but please Canon give it some faster AF and whilst your at it IS ) and if you could ensure it sells for less than the new Nikon everyone (apart from Nikon users) will be very happy.

Its not made to be the sharpest 50mm out there, its made to give great bokeh and correction to coma flare, CA and other aberrations.If you ever used the 1.8 or 1.4 50mm's you know how ugly they can by wide open.canons 50/1.2L doesn't fair much better in terms of come flares.I'll post 2 samples of come flares below, one canon 50/1.2L and one 58/1.4G, and I think you can guess which is which.http://tinyurl.com/olnflj9http://tinyurl.com/p7rpsmu

The usual lens paradox. Looking at some numbers, one asks himself why he or she should pay so much money for a glass. Yet those who have put their hands on the lens are ready to swear about the unique quality of the lens. As Yabokkie rightly said, there is much still to understand about lens design. And much about lens evaluation, too. One of my favourite lenses of the past, the M Summicron 35, had weak borders, that became decent, nothing more, by 5.6. Still it made wonderful photos. My old Nikon 105/2.5 AI is beaten in the numbers by any 90-105mm macro. Then shoot a portait, and you'll see the difference. I have the impression that pixel peeping does not help in judging the real virtues and possibility of any glass. We should seek other values.

this 58/1.4G is not designed for the focal plane only but for a 3D in-and-out-of-focus image space and it's value is distributed throught out that space.

old lenses were designed not only by knowledge and skill but also by luck, and the designers only knew part of the lenses they designed (if one thinks that lens design requires more calculation than artillery staffs do in a war and there are still a lot left in the dark).

I don't know if this is a good lens but Nikon say they designed it with thorough understanding of wavefront aberration, the mother of all aberrations and measured with high precision at more wavelengths than before and they are satisfied with the result.

Everyone on here comparing this to a standard 50mm lens is missing the point of this lens: It's a Noct lens. It's a speciality lens for shooting at night and low light. It will have no coma and excel for nighttime shooters. It does not need to be consistently sharp from edge to edge for those type of shots (and most shots are center subject focus even if we don't want to believe that).

First, I doubt that anybody wants to cut mustard with that lens.Second, the decision whether a price is to high or not will never be a fact but highly depends on ones personal needs the budget and emotions.I have the 24mm f/1.4, the 35mm f/1.4, the 50mm f/1.4 and the 85mm f/1.4 and I alwas had the problem to decide between the 35mm and the 85mm because I was never happy with the results of the 50mm. I even tried the Zeis 50mm 1.4, but it turned out to be quite troublesome without the AF. Now I got the 58mm f/1.4 and I´m really happy with it.I personally find the DxO results interesting but in the end the only thing that counts is the picture.

I definitely see why Zeiss made there new High-End 55mm f/1.4 Otus....and it looks like from what I have read..that they have made a beauty. 12 elements in 10 groups. WOW!.... Huge, MF and pay dearly.. but WHAT a lens.

I do not know why Nikon made this lens? (I do need to read other reviews to get a more well-rounded, complete story.. as I am not a fan of dXo..), It is baffling if these results in third party testing are accurate.

Thanks Samhain for the link...interesting read...I am still not convinced @$1700...I feel that Sam was truly impressed with the lens although he was trying to convince himself that he was...I will stick with my Sigma!!!

An auto-focus alternative to the 50mm f1.2 AIS. Nice. The price just may make it a very rare lens though. Wow! $1,700? That seems cost-prohibitive to me. Of course, the 85mm f1.4 is expensive too, and that sells, right?

This lens performs modest on these type of test because Nikon designed NOT to do well.58/1.4G designer Haruo Sato expects such result, stating that aberration is controlled to have smooth background bokeh at close distance instead of persuing sharpness. The lens is uniquely designed to have different character depending on subject distance, with more sharpness at infinite and less so (with pleasant bokeh) as getting closer. Sato says those character remains unless shooting at smaller aperture such as f/8 or f/11.

I had the Voigt but I sold it. My eyes are getting old and it is getting difficult to manually focus when DOF are thin. The Voigts do have great color rendering and micro-contrast. However, I think the Nikkor is a tad better than the Voigt, but not 3 times better. But then, you can't always use the difference in price to judge the incremental IQ. Sometimes it takes a lot of costly exotic glass elements to get rid of a slight coma, fringing etc.

I'm not a fan of marketing names like "x", "i", "pro" or other cool sounding nonsense (even "Apo" which means something, is often used dishonestly). But the comments here clearly show people have no idea why this lens costs more than a regular 50/1.4 lens. Maybe marking the lens somehow would provide a clue.

For this kind of money, with today's technology and Nikon's expertise, the lens should be perfect. If they're not going to come out with something that just stomps everything else into the dust, which they should be able to, this lens simply isn't necessary.

Initially I thought this is Nikon's answer to ZEISS Otus, sharp from center to corner. But according to early tests, it is indeed very sharp at the center AND corner, but not uniformly sharp. As Roger Cicala reported in his test - "sort of a ‘moustache’ field curvature".

But like everybody says, sharpness is not everything(plus I don't have a Nikon body and it's kind of expensive).

Back in the day, weren't 58mm lenses produced as a compromise? Among the easier to design/build and thus cheaper, and photographers hated that because they didn't want the FL to just get longer for a normal prime.

Then again, the easier it is to put together, the more time and effort can be put into perfecting the optical formula~

usually when using a large aperture lens at open, one should better focus at the center and trim to the wanted framing for that's the most efficient way, by trading off some image quality. it's quite thoughtless if someone want's to be "perfect."

agree the price is too high. some products are more for the designers themselves than ordinary users. 58/1.4G and Df are good examples.

Some posters here think they are the center of the photographic universe. If some piece of gear does not appeal to THEM than it must appeal to NOBODY and the company producing it must either be stupid or self indulgent.

Everyone talks about how great the Sigma Art 35 is and how it will kick Nikon's butt WHEN they come out with other focal lengths. I wonder have you all counted the number of duds Sigma has produced over the years compared to its one great lens?

I'm sorry....I know Sigma appears to have turned a corner but if you had told me, 2-3 years ago that photo enthusiasts were favoring a Sigma lens over a Nikon, Canon or, heck, a Tokina lens, I would not have believed it. Maybe I'm stuck in the past, having seen too many lenses fall apart. Next thing, they'll be saying Sigma has higher resale value than Nikon.

If I shot Nikon, I'd be getting this lens. The sample shots I've seen have been absolutely beautiful. The bokeh, coma, rendering, micro contrast, 3-d effect, etc, just lovely results.I've learned to not put so much stock into numbers & resolution testing and focus more on real life shots/examples of what the lens can produce. There's so much more to a lens than numbers. For a landscape lens- yes I want max sharpness. But for a portrait lens, I'm much more concerned with rendering characteristics. does it have 'mojo'?

I've owned lenses that didn't test well but the results were breathtaking. My old (made in Japan) Pentax 77mm is a prime example. That lens can produce portraits that are down right haunting. Rendering & characteristics that I couldn't get out of a canon 85/1.2 or Sony Zeiss 135/1.8. Both of those lenses are best of the best portrait lenses, yet the Pentax 77(especially on a FF film camera) could just do spooky things that I could never recreate with other lenses.

I love his findings:"Not worth the money, but has more character than anything that costs less."

My question is if he had done similar photos with say a Sigma 50mm f/1.4 how much different would they really be? I know he has one comparison shot, but I mean if he had done similar types of shooting for an entire set (not side by side).

@Samhain, I don't know, the SMCP FA 77mm f/1.8 tests very well, at least when I tested it.

I agree, there are more to lens tests than resolution, but resolution is important, especially with digital manipulation. You can add all the character you want in post processing.

One thing that is nice about the 58mm though is the focal length is notably tighter than other 50mm class lenses, so that is worth something.

@viking79 For me, I don't really feel the need to see comparison shots with the sigma. That guy is (obviously)an extremely taIented professional who knows lenses - if he says he loves and uses the sigma on a regular basis, and that he prefers the Nikon 58 results, I'll take his word for it.

As for resolution- I didn't see any resolution issues with any of his photos. Did you? If anything, there was a couple that were almost TOO sharp for portraits(see the b&w closeup of the wedding couple- you can see every little flaw in her skin/makeup). I just don't see any resolution issues with this lens in real world use. Ive yet to see one photo anywhere that made me question if this lens isn't sharp enough.

You can't judge resolution by those tiny web sized images. There's was also no aperture info available. All full res samples I have seen so far suggests that the 58mm has to be stopped past f2 to get decent performance. At f1.4 Nikkor 58mm is just not very good at all...

Compare this to Otus 55/1.5 which got very high performance straight from f1.4 and creamy bokeh. The Sony 55/1.8 FE is very sharp wide open too and seems to be an excellent lens.

Also bokeh qualities can't be judged without reference shots with other lenses from exactly the same spot and background. I bet those photos would have looked OK with about any other 50-58mm/1.4 lens out there. It is not about the tool anymore but examples of fine photography which is completely different thing.

People talk about lack of CA but still there's LOCA present. Contrast is not so good @ f1.4.

Look at the rest of his gallery and blog and you will see tons of beautiful pictures. He uses Sigma in 50mm and 85mm FL. You should be able to tell which is which. Beautiful work. I wish he didn't strip the EXIF.

@howaboutraw I could care less about seeing the raw pre-pp photos, I want to see the finished product. I shoot for finished product, not stripped down raws.

The guy owns & shoots with the sigma 50 and noct 58/1.2 professionally- if he says this lens is better than the sigma & as good/better than noct, I have no reason not to believe him. I'm not routing against this lens like some are in this comment section...

@darkshift why would I compare this to the Otis? The Otis is $4k and almost as big as a 200mm 2.8. But for fun- from all the shots I've seen from the Otis- I wasn't impressed at all by the bokeh. It strikes me as one of those Zeiss lens designed for maximum sharpness above everything else. The Nikon 58 is the opposite of that.

I don't get it. According to the dprevirew test (performed by DXO?) $500 Sigma 50/1.4 (which has GREAT bokeh!) tested on the same camera (D800) is better than this 58/1.4 at f/1.4, about the same at f/2.8 (a bit lower in the center (which is not a meaningful point anyway for both are beyond Nyquist frequency) and a bit better at the edges), data for F2 is missing for Sigma for whatever reason. What is the point of this lens again?

Even lowly Nikon 50/1.8 tested on D3X (not on D800!) matches the 58/1.4 in resolution at f/2...

Resolution is only part of the story. I used own the Sigma 50 f/1.4 and color/contrast is not one of its strengths. For example, it's nowhere near my nano coated 28 f/1.8G in that area. And a high grade Nikkor like the 58 f/1.4 from the reviews I've read has impressively high color/contrast and bokeh.

The Sigma 50 is a good bank for the buck lens, but it's not in the same class as a higher grade Nikkor for rendering or color/contrast.

Well, if you're serious about photography - you should have a color checker to fix the color issues. So this leaves 58 with only one possible advantage over Sigma - contrast. While Sigma is sharper. So... either more resolution or more contrast. Contrast to a degree can be fixed in Lightroom, missing details cannot be added though. Ergo: Sigma wins.

And if you are serious about photography, you would know there's more to a lens than sharpness.And what's with the color checker argument? how do you fix color issues if the lens can't render the colors like it should in the first place?

That's what's wrong with all the math and testing. With special purpose lenses, the numbers absolutely do lie and lead to silly comparisons like one camera gets an 89, so it's better than one that gets an 87.

I think everyone is missing a key element (and even DPREVIEW) doesn't list the full name for this lens: It's a NOCT lens. As in nocturnal/night time lens. Yes, it's obviously great for daytime uses, but it's a killer at night. You will see almost no coma. None.

Which is why I'll wait for a professional lens review site like Lenstip to test this lens as not only are their MTF 50 resolution graphs a lot less cryptic than DxOMark's M-Pix system, but Lenstip also tests for coma, astigmatism, bokeh, ghosting and flare. Essentially all the things that optical engineers have to address when designing a lens are covered in their tests.

We'll likely see that coma is corrected much more effectively on the 58 f/1.4 than on the other Nikon 50s.

Looked at the DxO lens measurements. The 35 mm Samyang seems amazing. May zoom into the digital file. Naturally, not automatic. To me specs center to corner are most importan. The Zeiss comes very close on the Sony RX. Sigma?

This Nikon: Good not great, fully overpriced lens compared to value. I have some Nikon cameras and mostly use third party lenses (with DxO 9, is ok) = better and for less. But, the Nikon sensors and camera ergonomics are great.

From what I've seen, the Zeiss is really something. The Leica lens is hand assembled and tested in Germany which won't be visible in images but explains part of the cost. One could argue that all 3 of these lenses are overpriced...or that if you can't afford them, you're not a pro. Then a gain, my neighbor is a neurosurgeon so his salary makes him a pro.

Sony alpha rumors has some MTF curves for the Zeiss 55mm f/1.4 and the new Sony/Zeiss 55 f/1.8. The Sony looks good at f/1.8 but the Ottus looks really really good, high resolution across the whole frame from f/1.4.

@HowaboutRAW: We are talking about Nikon, something more "acessible" to the comun mortal, or supposedly accessible.

Surely if we are talking about lenses made ​​by special manufacturers, as the Zeiss or Leica they have their own niche, we have to take into account them to maintain their status has to keep prices too high, but do not doubt that are too high to the product offering. Obviously whoever makes the price is supply vs. demand also. And there's always people for the most exclusive luxury, which in practice is not synonymous with quality improvement to justify the crazy prices in its work.

I be a modest person, always raised the price of quality vs. cost vs. need. Sure, personally I do not see myself paying ~$4000 for a Zeiss or Leica M 50mm f2.0 for $~7000. My work did not improve nearly 400% for sure with these lenses. Just my humble opinion. Always rather have a Porsche than a Ferrari, for numerous reasons. Personal reasons of course.

Looking at DXOMark they have results for the Sony 50mm f/1.8 on NEX 7 and Nikkor 58mm f/1.4G on D7100 (same resolution), and over shared aperture range Sony looks much better. So if looking to use the lenses on APS-C, the Sony is definitely nicer on paper.

Comparing on Nikon full frame, the 58mm f/1.4G to the 50mm f/1.4G, it is a big improvement in the center. It shows how the 50mm f/1.4G is not that great of a lens (I always though the 1.8G was just as good for half the money).

I am curious as to how the new Zeiss 55mm f/1.8G does. My guess is moderate aperture will give it a better value/performance metric than the new Nikkor 58mm f/1.4G.

The much cheaper 50mm f/1.4G is not bad at coma according to lenstip. Noct or not, the lens is expensive and not as good looking as the Sigma 50mm f/1.4 (which also has minimal coma, according to lenstip). The 58mm also has so-so light transmission, worse than I would have hoped. I am curious as to how the Zeiss 55mm f/1.8 will perform on A7, might be a relative value next to the Nikkor 58mm f/1.4G, and to think people thought it was expensive at just over half the price of the Nikkor.

Why exactly would you use lens on a 3rd party body when you got perfectly fine 1st party bodies?A7 is mirrorless designed for short flange lenses. Not a DSLR. Comparing lenses on that is pointless waste of time.

As someone who had no intent of purchasing this lens; but upon testing it out on the D600 I did end up buying it, sharpness was but one factor. To my eye (and in comparison to my current 50mm f1.4 G) this new 58mm was far sharper at the focus point at f1.4. The out of focus areas were rendered quite nicely and the way the photo is drawn by the lens is what attracted me. I rarely read MTF charts because, what/how I shoot, I often don't care or worry about the corners.

This lens has replaced my 50mm (I sold it the same day) and I will be happy to keep the 58mm and 35mm as my main shooting lenses. Heck, the 58mm may even replace the 85mm f1.4 D I still own.

Other than price there doesn't seem much to complain about considering that most large aperture lenses are not bitingly sharp straight from max aperture.

But the 58 f/1.4 has some crucial differences and advantages over similar lenses:

* Color/contrast easily surpasses other 50s as expected from a high grade Nano Coated Nikkor. * Resolution as good or better than to other 50s* Bokeh is significantly creamier, more refined * Metal barrel, high build quality as expected for the price

> I can enhance colour and contrast quite easily within Lightroom and Photoshop. Do I really need to spend another £1700 to get it?

Increased color/contrast found in professional grade lenses like the nano coated Nikkors is not the only advantage of the more modern coating process. You also get significantly better flare control. Only you can decide if the extra money is worth it.

No you can't. You can amp what's there. You can't create color and contrast that weren't captured. Sharpness is defined by contrast. Better lenses have more contrast at finer scales. Increasing contrast in photoshop exaggerates what you have. What you don't have isn't there to adjust.

If what you said was true, the difference in sharpness between a Leica S lens and the cheapest Samyang would be the contrast slider. It's not.

the Canon L 50mm has a very low rating on photozone.de, still by far my favorite standard lens when shooting Canon. The Nikkor 58mm will conquer the hearts of many, the only reason to get this type of lens is to shoot wide open or close to wide open. Lack of resolution isn't the problem, but CA, astigmatism and especially coma can ruin a shot. Time for MTF reviewers to update their methodology, center sharpness at f11 for this type of lens is as meaningful as the achievable top speed of a sports car in reverse. Price, about $500 too expensive

Have you checked its transmission? I bought a 50 mm Rokkor X PG hoping that it would be a stop brighter than my ZD f2 macro. It was only about 1/3 of a stop brighter, and although very sharp for an f1.4 of its generation, nowhere near as sharp wide open as the ZD. It does have a shallower DOF wide open so I have kept it, but mostly these days I use the equally bright and much sharper mZD 45mm f1.8 -which also auto focuses very quickly. At 90mm/f2.5 equivalent FOV/DOF to the Nikon not a strict replacement for a 58 mm ff - but less than 1/3 the cost.

The Rokkor-X PG is indeed a very nice lens. Its transmission is due to its coatings, I assume. But it is a fast lens on my NEX and I like the bokeh. And for less than 50 bucks (you can find it for much less if you search), it is a steal of a lens!

There are a lot of old Minolta lenses that are awesome. I have rediscovered my old Minolta MC and MD lenses for my Micro 4/3 system. They do an awesome job and colors are very consistent from lens to lens. Although I would avoid the Minolta lenses with the 49mm filter threads, they don't seem to be as smooth or well build.

If the sensor outresolves the lens, there is no need for AA filter, for instance. Also, the 'blur' will be rendered differently, (which may have no value at all) Look at it this way, if the pixel count is high enough, you get the maximum out of all your lenses.

The Fuji 14mm f/2.8 is optically corrected. I think the 35mm is too. Software corrections are fine, no reason to correct lateral CA optically, we aren't shooting slide film, it is easy to scale magnification of color layers in software. Correcting optically also has design tradeoffs in the lens performance. It is not a win-win for optical corrections.

The fuji 35 1.4 is not fully corrected! It's software corrected, if you doubt it just open one image on CS3 and compare it with the same image opened on Lightroom5. It has geometric distortion that is corrected behind the scenes by the camera's JPG engine. And it isn't an Apochromatic lens at all so definitely is not fully corrected.

Are you guys incapable of reading the English language? You don't have to agree with the way DXO scores, but they did clearly state the reason they knocked the score down. That reason is: not being sharp wide open and not being sharp across the frame until f11. How do you people make it through life without a basic reading comprehension ability?

"On the downside, sharpness is low at full-aperture and isn’t uniform across the frame until its stopped to f11. At larger apertures there’s as much as 30% deviation in sharpness from the center to corners."

"Individually the new Nikkor has the higher sharpness overall but the current 50mm is sharper at full aperture, while both are sharper than the AF-D model.

Stopped down to f2.8 and the new Nikkor is sharper in the centers than either but the outer field, edges and corners are similar to the old AF-D model and someway behind the current 50mm model until f11, where the new 58mm has high sharpness from corner-to-corner."

I don't think that the problem is reading the graphs, more of interpretation i.e. how do the graphs translate into practical use of the lens. I find DPR's 'real world' samples far more revealing than these graphs.

We need a new metric that is not accounted for called 'rendering'. This is the same metric that enables us to say that this black and thin audio cable sounds a little 'tinny', but this more expensive red and white intertwined audio cable with a shiny nylon wrapping sounds 'full' and 'expansive'.

But in truth there are some lens testing methodologies that I wonder can be supplemented, for example the center point should not *always* be considered the 'reference' plane of focus, but another set of measurements should be made at mid-frame as the 'reference' plane of focus. So tests should not only test center resolution and measure from there, but establish midframe reference point as well.

Indeed, it is well established that our brain "renders" objective data from our senses into subjective impressions that can be far from the truth.

So we need raw numbers from testing, and then come with solid interprations without applying our old nemesis "in my experience". On top of that, as Roger Cicala has shown us, any meaningfull conclusion HAS to involve several copies of any lens to deal with sample variation. (something review sites choose to neglect for practical reasons, and another pitfal for people's "own impression") DxO Mark is on the right track, but they need more parameters that measure important characteristics of lenses. Your suggestion of using mid-frame focussing is a nice idea. Moreover, they should figure out how to put into objective numbers things like overall and local contrast, colour "rendering" (sorry for using that awfull word), bokeh... Their magical final scores are very incomplete, hence almost useless. DPReview's final scores are not much better...

"... for example the center point should not *always* be considered the 'reference' plane of focus ..." True! now it is very hard to understand if the lens is soft, or the focusplane is elsewhere. Or how much it curves. And, yes, more parameters should be tested, like quantifying bokeh. But what is the additional set of useful test parameters?

Bokeh is merely how out-of-focus areas are displayed, it's not some mythical property. It's most noticable on OOF highlights, hence a test could be a couple of controlled "highlights" (single versus groups of leds for instance) distributed across the field of view and photographed by focussing on a target a given amount in front and behind the highlights. Lenstip does a quite good job of this, although unfortunately their analyses doesn't go as far as analyzing the results with image analyses tools. This would not be difficult to do by the way - for instance, levels could be plotted against diagonals through the OOF highlight, and this would show how smooth the transition from dark to light is and how evenly the light level is within the highlight. Also, as a function of f-stop, it would be possible to calculate the difference from a perfect circle etc.

Btw, beauty can easily be quantified as well: http://www.livescience.com/7023-rules-attraction-game-love.html Much like with bokeh, it's all about good symmetry... And when it comes to the bouquet of wine, see here to learn how easy the human brain is fooled: http://www.tastingscience.info/publications/Color_on_Wine.pdf (sorry for the poor quality, but figure 6 is a beautiful example of how differently coloured wine is described differently, even though the taste is exactly the same) There's a lot of science that shows how easy our perception of the world around us is influenced by internal and external factors - main conclusion: be sceptical of your own or other people's "judgment" of things. If it's not something that was measured, it's most likely skewed by perception...